ChromaStarServer (formerly GrayStarServer) is a stellar atmospheric modeling and spectrum synthesis code of pedagogical accuracy that is accessible in any web browser on commonplace computational devices and that runs on a timescale of a few seconds.

A Python version of this software, ChromaStarPy (ascl:2504.020), is available.

ChromaStar (formerly GrayStar) is a web-based pedagogical stellar model. It approximates stellar atmospheric and spectral line modeling in JavaScript with visualization in HTML. It is suitable for a wide range of education and public outreach levels depending on which optional plots and print-outs are turned on. All plots and renderings are pure basic HTML and the plotting module contains original HTML procedures for automatically scaling and graduating x- and y-axes.

ChromaStarPy computes the vertical structure of a static, plane-parallel, one-dimensional stellar atmosphere in local thermodynamic equilibrium (LTE); it also computes the emergent spectrum incorporating opacity computed with a comprehensive atomic line list from the NIST Atomic Spectra Database. The code provides post-processed data products that are ready to visualize in a Python IDE such as spyder. ChromaStarPy is a port of ChromaStarServer (ascl:1701.009); the code enables users to experiment with and develop a stellar astrophysical modeling code in a graphical IDE, and to compare observational data to ad hoc model output.